In embedded system, the driver is very important. In the period of porting system, the main task is programming the drivers. In kinds of drivers, the block driver is an important type of driver which affects the system's performance.In kinds of memory used in embedded system, Flash is the most popular device. Many handhelds such as Phone, PDA, MP3 player, USB storage and so on, use Flash as their storage. At present in the market, there are mainly two types of Flash: one is NOR Flash which is used widely, the other is NAND Flash. NOR Flash is excellent for XIP (eXecute In Place). And its speed of random reading is fast. However, NAND Flash which is favored by the industry at present has very high packing density, and the production flow is very simple. NOR Flash has the high bit-cost and the lower capacity. Howerever, NAND Flash with high capacity and low price appears the strong market competitive power, its emergence provide the very good solution for reducing the storage cost.The aim of the research is to implement and optimize the block device drivers in embedded Linux based on the XScale framework. include RAM device, MTD device and MMC card driver. Among them, MTD device is a special device which supports better manager to devices based on Flash. And now MTD device's usage in embedded system is increasing quickly.All the work described in the paper has been finished now and has succeeded in running stably on the development platform. Meanwhile, the product based on the platform described in the paper has come into the market successfully. |